1. Field of the Invention
The present invention relates to a continuously variable valve lift apparatus. More particularly, the present invention relates to a continuously variable valve lift apparatus for varying the lift amount of a valve corresponding to driving conditions of an engine.
2. Description of Related Art
An internal combustion engine generates power by burning fuel in a combustion chamber in an air media that is drawn into the chamber. Intake valves are operated by a camshaft in order to intake the air, and the air is drawn into the combustion chamber while the intake valves are open. In addition, exhaust valves are operated by the camshaft, and a combustion gas is exhausted from the combustion chamber while the exhaust valves are open.
An optimal operation of the intake valves and the exhaust valves depends on a rotation speed of the engine. That is, an optimal lift or optimal opening/closing timing of the valves depends on the rotation speed of the engine. For example, research has been undertaken for a variable valve lift (VVL) apparatus that enables different lifts depending on engine speed, and for a variable valve timing (VVT) apparatus that opens/closes the valves with different timing depending on the engine speed.
For such a VVL apparatus, it is recommended that power loss in driving the valves using torque of the camshaft is minimized. In addition, it is recommended that the VVL apparatus is symmetrically designed such that it may be symmetrically installed in both banks in a V-engine.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.